This is a strange day for you in the emergency department. Now you have to treat another normovolemic patient with acute drug-induced hypotension, and give the usually correct and effective dose of phenylephrine. This time the drug causes a vasopressor response that is far greater than you've ever encountered: systolic pressure rises dramatically, if not dangerously. Which of the following drugs did the patient most likely take an overdose of?

Correct Answer: D

Rationale: The correct answer is D: Reserpine. Reserpine is a drug that depletes catecholamines like norepinephrine and dopamine from nerve endings, leading to a prolonged and exaggerated response to sympathomimetic drugs like phenylephrine. This results in a dramatic increase in blood pressure when phenylephrine is given. Rationale: 1. Atenolol (A) is a beta-blocker and would not lead to a vasopressor response. 2. Bethanechol (B) is a cholinergic agonist and would not lead to a vasopressor response. 3. Prazosin (C) is an alpha-1 adrenergic antagonist and would not lead to a vasopressor response. In summary, Reserpine is the correct answer because it depletes catecholamines, leading to an exaggerated response to sympathomimetic drugs like phenylephrine, resulting in

Correct Answer: D

Rationale: The correct answer is D: Salbutamol. Salbutamol is a selective β2 adrenoceptor agonist. It has a higher affinity for β2 receptors compared to β1 receptors, leading to bronchodilation without significant effects on the heart. A: Adrenaline and C: Isoprenaline stimulate both β1 and β2 receptors, causing increased heart rate and bronchodilation. B: Noradrenaline stimulates α1, α2, and β1 receptors, leading to vasoconstriction and increased heart rate. Therefore, salbutamol is the only drug that selectively stimulates β2 adrenoceptors, making it the correct choice.

Correct Answer: D

Rationale: The correct answer is D: Diarrhea. Atropine is an anticholinergic drug that typically causes dry mouth, tachycardia, and blurred vision as side effects due to its mechanism of blocking acetylcholine receptors. However, diarrhea is not a common side effect of atropine. It is important to differentiate the expected side effects of a drug from those that are not commonly associated with it based on its pharmacological actions.

Correct Answer: C

Rationale: Adrenaline, also known as epinephrine, is a hormone that activates the fight-or-flight response. It causes bronchial muscle relaxation (A), increases cardiac contractility (B), and increases sweat secretion (D) to prepare the body for action. However, adrenaline inhibits intestinal motility (C) to conserve energy for vital functions during stressful situations. Therefore, the correct answer is C because adrenaline does not increase intestinal motility. Relaxation of bronchial muscle, increased cardiac contractility, and increased sweat secretion are all effects of adrenaline, making choices A, B, and D incorrect, respectively.

Correct Answer: C

Rationale: Rationale: - Noradrenaline stimulates both α and β receptors, leading to increased heart rate and vasoconstriction. - It does not decrease heart rate; it actually increases heart rate due to its actions on β receptors. - Noradrenaline causes vasoconstriction by activating α receptors, leading to increased blood pressure. - The incorrect statement is C, as noradrenaline actually increases blood pressure by causing vasoconstriction.